Objective:

Background:

Accidental air embolism is a rare cause of ischemic stroke that is becoming increasingly well-described in the literature. However, the mechanism and severity of this type of injury can vary, with significant ischemia typically emerging early in the course of care. To our knowledge, delayed ischemia in this setting has rarely been described.

Design/Methods:

We describe a hospitalized patient who developed cryptogenic air emboli resulting in acute neurologic changes that appeared to improve with emergent care. However, follow up imaging revealed delayed ischemia not identified on initial radiography.

Results:

A stroke code was called for an unresponsive, hospitalized 75-year-old man. On evaluation, he was found to be obtunded with forced left gaze deviation concerning for possible non-convulsive status epilepticus (NCSE). He was treated acutely for seizure and subsequent stat CT head revealed air within the right greater than left hemispheric cortical veins with loss of sulcation, concerning for developing ischemia. On review of his hospitalization, prior TTE showed no PFO. Retrograde movement of air into the cortical veins was the hypothesized etiology,¹ but the source of the air in this case remains cryptogenic. MRI obtained 5.75 hours after the patient’s last known well showed subtle diffusion restriction without definitive cortical infarction and follow up CT head approximately 13 hours afterward showed near complete resolution of the air emboli. However, MRI 4 days later demonstrated diffusion restriction and cerebral edema throughout multiple vascular territories, consistent with venous infarction.

Conclusions:

This case highlights that venous air emboli can cause delayed ischemia that may not be appreciated on initial dedicated brain imaging. As such, affected patients may require intensive neurocritical care irrespective of initial radiographic findings.